1/5 JSM Clin Cytol Pathol 5: 5 JSM Clinical Cytology and Pathology Submitted: 01 March 2020 | Accepted: 16 March 2020 | Published: 18 March 2020 *Corresponding author: YassinNayel, Department of Pathology, American University of the Caribbean School of Medicine, USA (#1 University Drive at Jordan Road, Cupecoy, Sint Maarten),Tel: 604-815-8929; Email: yassinnayel@students.aucmed.edu Copyright: © 2020 Nayel Y, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Citation: Nayel Y, Jackson G, Taylor M, Varney J, Alkhoudr N, et al. (2020) Extraskeletal Myxoid Chondrosarcoma in Comparison to Myxoid Liposar- coma - Case Report of a Challenging Diagnosis and Brief Review of the Literature. JSM Clin Cytol Pathol 5: 5. Extraskeletal Myxoid Chondrosarcoma in Comparison to Myxoid Liposarcoma - Case Report of a Challenging Diagnosis and Brief Review of the Literature Yassin Nayel 1 *, Garrett Jackson 1 , Matilda Taylor 2 , Joseph Varney 1 , Nour Alkhoudr 1 , Kollin Kahler 1 , and Mohamed Aziz 1 1 Department of Pathology, American University of the Caribbean School of Medicine, USA 2 Quest University Canada, BC, Canada Abstract Extraskeletalmyxoidchondrosarcoma is an uncommon soft tissue sarcoma that can resemble a much more common sarcoma, myxoidliposarcoma, leading to misdiagnosis. This has important clinical implications as these pathologies differ in treatment, recurrence rates, and metastasis. Here, we present a case of a 29-year-old man, who presented with a large soft tissue mass at the front of the left ankle. This case presented a diagnostic challenge based on histomorphology and IHC studies alone. Molecular testing was essential for defnitive diagnosis due to lack of agreement among soft tissue pathology experts. Reporting cases of EMC is imperative in order to bridge the gap between the known pathological features of this tumor and the consideration of this neoplasm in differential diagnoses. Abbreviations ML: Myxoid Liposarcoma; EMC: Extraskeletal Myxoid Chondrosarcoma; IHC: Immunohistochemical Introduction Liposarcoma, a tumor of lipoblasts, is the most common soft tissue sarcoma in adults involving deep soft tissues. Among other sites, it can be found in the retroperitoneum and popliteal fossa [1]. One genetically distinct variant of liposarcoma, myxoidliposarcoma (ML), is characterized by a t(12:16) translocation combining the DDIT3 gene on Chr. 12 with the FUS gene on Chr. 16 [2]. ML represents 30-50% of all liposarcoma cases [3]. It mostly occurs in the lower extremities and has a propensity to metastasize to non-pulmonary soft tissues, such as bone or the contralateral limb [3]. A characteristic of ML is a round cell component composed of uniform oval-shaped cells and signet-ring cell lipoblasts on a background of myxoidstroma. The presence of this small round cell component in more than 5% of the tumor mass is indicative of an aggressive behavior [4]. An additional sarcoma with a similar round cell component is extraskeletalmyxoidchondrosarcoma (EMC), which on clinicopathological findings is similar to ML [5]. First described by Stout and Verner in 1953 [6], this sarcoma accounts for less than 2.5% of all soft tissue sarcomas [7]. The rare occurrence of EMC, along with its similar presentations to ML, often leads to misdiagnosis and underrepresentation of EMC due to the lack of its consideration as part of the differential diagnosis [8]. EMC has specific pathological features, immunohistochemical (IHC) profile, and is characterized by a specific genetic translocation that can aid in a proper diagnosis [9]. We present a case of EMC that presented a diagnostic challenge on the basis of histomorphology and IHC studies alone and highlights the importance of molecular studies that were essential for definitive diagnosis. Case Presentation A 29-year-old male presented with a large soft tissue mass measuring 6.5 X 3 cm at the front of the left ankle.Magnetic resonance imaging (MRI) revealed a soft tissue tumor mass with an isointense signal at the front of the lower part of the left tibia (Figure 1A). A small core biopsy was performed, but the diagnosis was inconclusive.The mass was excised, and gross findings showed a relatively well demarcated tumor mass encased by a pseudocapsule. It divided into multiple gelatinous nodules by fibrous septa. Multifocal intramural cysts and hemorrhage were also seen (Figure 1B). Microscopic examination revealed a large, relatively well-demarcated, multinodular tumor contained by a pseudo fibromembranous capsule. The tumor consisted of myxoid areas containing cords and cellular aggregates of mesenchymal cells demarcated by dense fibrous septa. The cellular component displayed a spectrum of histomorphology. The cells predominantly formed linear cords and small aggregates, and some areas showed a complex cribriform appearance. Rhabdoid- like cells with eccentric hyaline globules were occasionally found within the tumor. The tumor showed focal cellular areas composed of large cells with vesicular nuclei and deeply Case Report © Nayel Y, et al. 2020